Tell me about the burden of proof...

The obvious standard is that the prosecution must prove their case beyond a reasonable doubt. A defendant is not required to testify. They can remain simply silent, and in the end, ask for a dismissal based on the prosecution's ability (or lack of) to prove guilt beyond reasonable doubt.

Since Zimmerman openly admits he shot Martin, but claims it was done only in self defense, does his defense now assume some responsibility to prove those claims? Can the defense make any claim at all, and will a jury be instructed to assume such a claim is a fact?

Is there any responsibility (whether legal or merely practical) which is placed on the defense to support their version of events?

1. All that is required is reasonable doubt.

Against the charges of second degree murder, unless the jury has the option of lesser charges, e.g., manslaughter.

Even then it must rise above reasonable doubt, which is left up to the jury to decide.

That's the way it was framed by the judge in my experience with a criminal jury trial. We acquitted because the prosecution witnesses had divergent and conflicting testimony (BTW, all police officers). The first vote was 10-2 to acquit. It went to 11-1, with only the foreman voting to convict -- he was a bit of a jerk IMHO. Finally, he relented and joined the rest, but with great reluctance.

2. Actually, since Zimmerman is claiming self defense

the burden of proof shifts. In what's called an affirmative defense, the person charged with the offense admits doing it, but claims legal justification to legally exonerate him. In that case the burden of proof shifts from the State to the person claiming the affirmative defense. I'm told that in Florida the law requires a lesser burden of proof from the Defendant, i.e. simply a 'preponderance of the evidence', i.e. 51% likely. Fla attorneys please feel free to correct me.

8. Not correct, 2nd degree murder defined:

782.04 (2)
The unlawful killing of a human being, when perpetrated by any act imminently dangerous to another and evincing a depraved mind regardless of human life, although without any premeditated design to effect the death of any particular individual, is murder in the second degree and constitutes a felony of the first degree, punishable by imprisonment for a term of years not exceeding life or as provided in s. 775.082, s. 775.083, or s. 775.084.

11. That's not intent. It's state of mind.

Intent is the desire to achieve the specific outcome of, for example, killing someone.

Intent is specific. Throwing a brick through a window may show a depraved indifference to human life, but it's not attempted murder unless the state can show it was thrown with the intent that it actually kill someone.

13. 782.07 Manslaugher:

In a nutshell, it includes death caused through negligence of a person in your care (senior, child, disabled); death of an officer or first responder cause by interfering with them while in the line of their duties; and any variety of deaths caused through the culpable negligence of some person's actions.

14. Interesting statute.

16. jury instructions on 782.04(2) ...

7.4 MURDER—SECOND DEGREE
§ 782.04(2), Fla.Stat.

To prove the crime of Second Degree Murder, the State must prove the following three elements beyond a reasonable doubt:
1. (Victim) is dead.
2. The death was caused by the criminal act of (defendant).
3. There was an unlawful killing of (victim) by an act imminently dangerous to another and demonstrating a depraved mind without regard for human life.

Definitions.
An “act” includes a series of related actions arising from and performed pursuant to a single design or purpose.

An act is “imminently dangerous to another and demonstrating a depraved mind” if it is an act or series of acts that:
1. a person of ordinary judgment would know is reasonably certain to kill or do serious bodily injury to another, and
2. is done from ill will, hatred, spite, or an evil intent, and
3. is of such a nature that the act itself indicates an indifference to human life.

In order to convict of Second Degree Murder, it is not necessary for the State to prove the defendant had an intent to cause death.

18. "demonstrating a depraved mind"

evidence of (1)--reasonably certain to kill or do serious bodily injury to another--and (3)--the act itself indicates an indifference to human life--could certainly be shown by Zimmerman's drawing of a gun and firing it toward a person. An act which Zimmerman freely admits to doing.

To prove 2nd degree murder now, all the prosecution has to show is ill will, hatred, spite, or an evil intent. If they show "Ill Will" through Zimmerman's comments and actions, and also by establishing that Zimmerman "initially provokes the use of force," they'll also manage to disqualify him from using a defense based on self defense.

19. Z has to try and convince the jury that the killing

was in self defense. The Prosecution will base its case in chief on the idea that 1) there was no self defense, therefore 2) Z killing him was done without legal justification. The burden is then on them to prove that beyond a reasonable doubt. They will try and establish as many facts through evidence presented and testimony as possible which indicate the depraved mind standard required for a verdict of Murder 2.

21. So if I ever claim self-defense I'm guilty until proven innocent.

22. In an affirmative defense you are admitting

that you committed act in question. There is no issue of presumption of innocence. The only thing in question is whether you can legally justify having done so. Self defense is one of those examples of an affirmative defense (insanity is another). Since you have already admitted the act it's your burden to convince a jury that you were justified in doing so.

5. As I understand it...

to prove second degree murder, the state must prove that the defendant actually intended to commit the murder. Manslaughter probably would have been easier to prove. A defendant can be convicted of that crime just for doing something stupid that leads to a death.

I don't think there is much chance Zimmerman will be convicted of second degree murder.

7. With COLGATE4's "affirmative defense" clue

775.027 Insanity defense.—
(1) AFFIRMATIVE DEFENSE.—All persons are presumed to be sane. It is an affirmative defense to a criminal prosecution that, at the time of the commission of the acts constituting the offense, the defendant was insane. Insanity is established when:
(a) The defendant had a mental infirmity, disease, or defect; and
(b) Because of this condition, the defendant:
1. Did not know what he or she was doing or its consequences; or
2. Although the defendant knew what he or she was doing and its consequences, the defendant did not know that what he or she was doing was wrong.

Mental infirmity, disease, or defect does not constitute a defense of insanity except as provided in this subsection.
(2) BURDEN OF PROOF.—The defendant has the burden of proving the defense of insanity by clear and convincing evidence.

So if affirmative defenses share a common burden, then "clear and convincing evidence" is the responsibility of Zimmerman's defense team.

“Clear and convincing evidence” is evidence that is precise, explicit, lacking in confusion, and of such weight that it produces a firm belief or conviction without hesitation about the matter in issue.

That's quite a burden. I think maybe some folks predicting that Zimmerman will walk are doing an early chicken count.

10. I think that's specific to the insanity defense.

The affirmative defense of self-defense in Florida, if the court finds it has been properly made out, must be defeated beyond a reasonable doubt.

In other words, if the defendant makes a case for self-defense, the state must both prove the elements of the crime beyond a reasonable doubt, and show beyond a reasonable doubt that it was not justified as self-defense.

Here's a 2012 decision out of the First DCA:

The defendant has the burden of presenting sufficient evidence that he acted in self-defense in order to be entitled to a jury instruction on the issue. But the presentation of such evidence does not change the elements of the offense at issue; rather, it merely requires the state to present evidence that establishes beyond a reasonable doubt that the defendant did not act in self-defense.

But the jury doesn't necessarily have to hear it that way. Still reasonable doubt, essentially, but this jury instruction was upheld:

An issue in this case is whether the defendant acted in self-defense. It is a defense to the offense with which is charged if the death of resulted from the justifiable use of deadly force. Deadly force means force likely to cause death or great bodily harm.

A person is justified in using deadly force if he reasonably believes that such force is necessary to prevent, one, imminent death or great bodily harm to himself or another, or, two, the imminent commission of aggravated battery against himself or another.
***
If in your consideration of the issue of self-defense, you have a reasonable doubt on the question of whether the defendant was justified in the use of deadly force, you should find the defendant not guilty. However, if from the evidence you are convinced that the defendant was not justified in the use of deadly force, you should find him guilty if all the elements of the charge have been proved.

12. Here's my understanding ...

Z has to produce evidence of self-defense (no burden of proof)

From FL case: "When self-defense is asserted, the defendant has the burden of producing enough evidence to establish a prima facie case demonstrating the justifiable use of force. Montijo v. State, 61 So. 3d 424, 427 (Fla. 5th DCA 2011); Fields v. State, 988 So. 2d 1185, 1188 (Fla. 5th DCA 2008); see Murray v. State, 937 So. 2d 277, 282 (Fla. 4th DCA 2006) (holding that law does not require defendant to prove self-defense to any standard measuring assurance of truth, exigency, near certainty, or even mere probability; defendant’s only burden is to offer facts from which his resort to force could have been reasonable). Once the defendant makes a prima facie showing of self- defense, the State has the burden of proving beyond a reasonable doubt that the defendant did not act in self-defense. Fields, 988 So. 2d at 1188. The burden of proving guilt beyond a reasonable doubt, including the burden of proving that the defendant did not act in self-defense, never shifts from the State to the defendant. Montijo, 61 So. 3d at 427; Fields, 988 So. 2d at 1188; see Monsansky v. State, 33 So. 3d 756 (Fla. 1st DCA 2010) (explaining that defendant has burden to present sufficient evidence that he acted in self-defense in order to be entitled to jury instruction on issue, but presentation of such evidence does not change elements of offense at issue; rather, it merely requires state to present evidence that establishes beyond reasonable doubt that defendant did not act in self-defense); Murray, 937 So. 2d at 279 (explaining that defendant in trial for aggravated battery was not required to prove self-defense claim beyond reasonable doubt or by preponderance of evidence; rather, self-defense evidence needed merely leave jury with reasonable doubt about whether he was justified in using deadly force).

So, the prosecution has to prove beyond a reasonable doubt all the elements of the crime charged and that Z did not act in self-defense.

The FL statute on self-defense:
776.012 Use of force in defense of person.—A person is justified in using force, except deadly force, against another when and to the extent that the person reasonably believes that such conduct is necessary to defend himself or herself or another against the other’s imminent use of unlawful force. However, a person is justified in the use of deadly force and does not have a duty to retreat if:
(1) He or she reasonably believes that such force is necessary to prevent imminent death or great bodily harm to himself or herself or another or to prevent the imminent commission of a forcible felony;...

I have not really been following the trial, but I assume this statute will apply:
776.041 Use of force by aggressor.—The justification described in the preceding sections of this chapter (justification of self-defense) is not available to a person who:
(2) Initially provokes the use of force against himself or herself, unless:
(a) Such force is so great that the person reasonably believes that he or she is in imminent danger of death or great bodily harm and that he or she has exhausted every reasonable means to escape such danger other than the use of force which is likely to cause death or great bodily harm to the assailant; or
(b) In good faith, the person withdraws from physical contact with the assailant and indicates clearly to the assailant that he or she desires to withdraw and terminate the use of force, but the assailant continues or resumes the use of force.

My understanding of FL case law on initial provocation is that the initial provocation must be done “by force or the threat of force.” For example, one case (Gibbs v State) ruled that "provoked" could not refer to mere words or conduct without force or threat of force.

Those who practice in FL may be able to add more to the legal standards that apply. I believe the jury instruction would be as follows: "If in your consideration of the issue of self-defense you have a reasonable doubt on the question of whether the defendant was justified in the use of deadly force, you should find the defendant not guilty. However, if from the evidence you are convinced that the defendant was not justified in the use of deadly force, you should find guilty if all the elements of the charge have been proved."

Edited to add: I'm from another state, so had to check FL law on all this. Hopefully if there are any material mistakes a FL atty will chime in.

23. Thank you.

He should have identified himself as a nosy overprotective neighbor...even if Martin was trying to hit him.

But Zimmerman was too caught up in the meme that the back kid was a thug, so he had to resort to calling the police....or deadly violence....instead of yelling out....whoa, stop hitting me, I'm just a nosy neighbor.